Worst case, you pass on the deal, no harm no foul.

Seriously, that lovely odor just rolled out when I started unwrapping the boxes.

If that liquid has an odor like pet urine or alcohol it stays with you for a long time.Just my nickel

No LESSEE or his family, guests, agents, or servants, shall make, permit or suffer any smoke or other odor, whether from a cigarette, pipe, cigar, cooking, cleaning, or other source, to be transmitted from his Unit to the common areas and facilities or to another Unit.

The odor from the porch was so strong that the upstairs tenant, who has only lived there for less than two months, had to burn incense in her apartment because of the odor.

Usually when you attempt to collect a debt and a borrower cries foul.

We removed all carpet and padding from all rooms in the house, but the "pet odors" from this room remain.

It will just foul up the chain of title and you will be asked to cure the defect for up to 25+ years after the fact. 

I have never heard an 80 year old swear in such a foul manner. 

Other people on here have had it happen, but its pretty rare in my experience.I still doubt they'd ever know, but if you transferred and they cried foul, you could probably just transfer it back, or if they want to be hard asses and call the loan due, you could just refi the thing.